My friend John lives on ______ floor so he takes the elevator(电梯)home every day.
There are many fish in this lake, and the birds can catch _________ food.
Mr. Green told us _____ turn the lights off when we leave the classroom.
Will you write a report ____ the wild animals ____ danger for the newspaper?
We must hurry up. We only have few minutes _______.
—Now lots of teenagers spend a lot of time playing computer games. —Yes. Teachers and their parents should prevent them ____________ too much.